Dear Authors,
If you believe that your paper was mistakenly rejected by other leading journals and you do not agree with final decision, the editors of Reports of Practical Oncology and Radiotherapy offer new fast track review. You may submit your manuscript to Reports of Practical Oncology and Radiotherapy together with all prior peer-reviews obtained from the other journal and your rebuttal letter. We guarantee review based decision within 72 hours from the time we will receive your manuscript.

Fast track submission process: Please submit the manuscript with all reviews and rebuttal letter by email to Dr. Michal Masternak ( for fast review processing. To assure immediate attention the email title must to include: RPOR-fast track- Last Name First Name (of corresponding author).

Volume 13, Number 1, 2008

Monte Carlo simulation of TLD response function: Scattered radiation field application

Alireza Shirazi, Seied Rabie Mahdavi, Ali Khodadadee, Mostafa Ghaffory, Asghar Mesbahi


Aim Thermoluminescent dosimeters (TLDs) have various applications in non-primary
beam dosimetry. Monte Carlo simulation of TLD response was done in low energy
beams to improve its clinical use in scattered beam dosimetry.
Materials/Methods TLD material made from LiF doped with Mg and Ti sized 3.1×3.1×1mm3 was used for experimental measurements as well as modelling by MCNP-4c Monte Carlo
simulation. TLDs were irradiated for different doses of beam qualities ranging
from 120, 180, 200, 250 to 300kVp x-rays generated from an orthovoltage machine
and 1.25MeV gamma rays from a Co-60 teletherapy unit at reference depth in a water phantom. The simulation conditions were the same as experimental conditions. The calibration factor, (CF)q, and its quality dependence factor, (F X Co), were defined as:
(CF)q = Calibration Dose/TL, (F XCo) = TL(X)/Dmed (X)
TL(X)/Dmed (Co)
Results The normalized values of measured quality dependence factors for different x-ray
beams were 1.28, 1.24, 1.16, 1.07 and 1.03 for different beam qualities, respectively.
Comparatively, the MCNP simulated fi ndings were 1.134, 1.96, 1.139, 1.052 and 1.034. The change of calibration factor with energy followed the equation CF=B0+B1E+B2E2+B3E3, where CF and E are calibration factor and energy (keV), respectively. B0, B1, B2, B3 are constants.
Conclusions Our findings showed signifi cant deviation of true dose value when TLDs are calibrated at different beam qualities. The greatest deviation was 19.9±2.1% in beam
quality of 120kVp. Obtaining a dose response curve may be helpful to calculate
the calibration factor with more precision.

Signature: Rep Pract Oncol Radiother, 2008; 13(1) : 23-28


« back


Indexed in: EMBASE®, the Excerpta Medica database, the Elsevier BIOBASE (Current Awareness in Biological Sciences) and in the Index Copernicus.